Typically, digital video test pattern generators store pixels for entire lines of video. For color bar patterns, there is much redundant data stored for solid color segments of a video line. The more complex the pattern, the more storage there must be to store all the video lines. This is further aggravated in high-definition video, in which there are more pixels per video line. For example, several kilobytes can be needed to store one line of video.
In the past, enough pixel memory was included in a generator to make up an entire line of video. For standard definition color bars, 1440 bytes of storage was needed for one video line (up to 3840 bytes are needed for high-definition video). As test pattern complexity increased, more video lines per pattern needed to be stored.
Therefore, a need exists for a more memory efficient test pattern generator for devices with display screens.